Answer:
25%
Step-by-step explanation:
If you start at 45% and it reduces by 20% you are just doing 45-20 which equals 25. (Please let me know if im wrong)
Answer:
a) The test statistic is 
b) The pvalue is 0.0060.
Step-by-step explanation:
Question a:
Ha: pB < pNY
This means that the alternate hypothesis is rewritten as:
While the null hypothesis is:
The test statistic is:
In which X is the sample mean, 
is the value tested at the null hypothesis and s is the standard error
pB = 0.581, pNY = 0.832
This means that 
0 is tested at the null hypothesis:
This means that 
Standard error = 0.1
This means that 
Test statistic:
The test statistic is
Question b:
The pvalue is the probability of finding a proportion less than -0.251, that is, a difference of at least 0.251, which is the pvalue of Z = -2.51.
Looking at the z-table, Z = -2.51 has a pvalue of 0.0060
The pvalue is 0.0060.
To figure out how many kids are in the school, you must set up an
equation with x representing the number of students. 30% of the students
are in the play, so that would be represented by 0.3x. We also know
that 140 students are not in the play, that could be represented by
x-140. These two equations will equal each other since they both
represent the same information, which is the number of children in the
play. You set those two equations equal to one another (0.3x = x-140).
You then can add 140 to the left side of the equation and subtract 0.3x
from the right side. We do this in order to get both values of x on the
same side of the equation. We then can simplify the right side of the
equation by subtracting 0.3x from 1x. We get 0.7x. Our equation now
looks like 140 = 0.7x. We must now divide each side of the equation by
0.7 in order to get the x all by itself and find its value. 140 divided
by 0.7 is 200. The number of students in the school is 200.
The statements that are true about this study are:
- This study uses random sampling.
-
This study uses a control group.
-
This study uses a repeated measures design.
Random sampling occurs when each sample has an equal probability of being chosen in a study.
This is seen in the random selection of 100 children. The Control group was used with the first group that had no screen time.
The repeated measures design was also used when multiple measurements were taken during different weeks.
Learn more about experiments here:
brainly.com/question/17216882
Answer:
The answer is b
Step-by-step explanation:
